The novel antibacterial organovermiculites with different mass ratios of chlorhexidine diacetate (CA) were successfully prepared by ion exchange reactions. The resultant organovermiculites were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal properties of prepared organovermiculites were investigated by simultaneous thermogravimetry (TG) and differential thermal analysis (DTA). The antibacterial activity of prepared organovemiculites against Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa was evaluated by finding minimum inhibitory concentration (MIC). Antibacterial studies showed that the organovermiculites strongly inhibited the growth of variety of microorganisms. (C) 2009 Elsevier Inc. All rights reserved.